John Smith wrote:

Len:

Phone lines are limited to roughly 38K by using the full audio bandwidth a
phone line is filtered to, with the early compression techniques. 56K is
obtained by improved data compression techniques.

Any line capable of supporting transmission of these audio freaks can
carry that much digital data (roughly +/-300hz to +/-5,000hz.

DSL is obtained by pulling all the filters from the line, audio bandwidth
is much expanded and much greater data can be crammed into that bandwidth,
with even greater efficient compression techniques.

Powerlines can support near/equal such bandwidths. With a bandwidth
allowing freqs to climb into the LF RF freqs, tremendous data speeds are
possible.... very localized interference to some rf freqs may be
generated... this is now in a testing phase...

Why this is so misunderstood is beyond explanation, or perhaps it is only
limited to the older generations, for some unknown reason--as any familiar
with technical details of data transmission methods and protocols should
know this, it is very basic stuff...


Only thing is that a DSL connection has a dedicated twisted pair
of wires, but BPL you have to share with everyone else in town.
Like cable modems, though the cable company cuts up their network so
only a handful of users share. With BPL the entire towns' users
have to share one channel. Now if you're the only user in town,
you got it made (unless a ham fires up his linear...)